The technology relates to radio communications, and in particular, to coordinating user equipment (UE) communications across different types of radio networks.
Heterogeneous radio access networks allow mobile radio communications operators to move traffic from a macro cellular radio network, where the capacity is sometimes limited, to cheaper shorter range wireless local area networks (WLANs) and femto/picocell networks connected over a variety of backhaul connections. Mobile radio connectivity thus may involve a mixture of radio, backhaul, and core network technologies, which require more complex inter-operator roaming agreements and emerging technologies.
3rd Generation Partnership Project (3GPP) establishes technical specifications for cellular radio communications. 3GPP also specifies mechanisms allowing non-3GPP accesses to connect to evolved packet core (EPC) networks at a packet data network-gateway (PDN-GW) using S2a, S2b, and S2c interfaces. These interfaces can be used by a 3GPP UE to attach to the PDN-GW (via wireline infrastructure) using Wi-Fi as access technology (Wi-Fi is the name given to the technology outlined in the IEEE 802.11 family of technical specifications). Prior to association to a Wi-Fi network, the UE must perform a network discovery and selection procedure. Both 3GPP and the Wi-Fi Alliance provide mechanisms that allow a UE to perform the discovery and selection procedures.
A 3GPP mechanism is the Access Network Discovery and Selection Function (ANDSF) defined by 3GPP. See 3GPP TS 23.402, the contents of which are incorporated herein by reference. An ANDSF either pushes to the UE or has the UE pull a set of rules that the UE uses to for scanning for Wi-Fi access based on the UE's location. Hot-Spot 2.0 (HS2.0) defined by the Wi-Fi Alliance, also incorporated herein by reference, is a network discovery and selection mechanism based on IEEE 802.11u. An HS2.0 objective is to allow a UE to seamlessly associate with a Wi-Fi access point based on a set of rules pre-installed on the UE. Hot-Spot 2.0 certification also provides a standardized mechanism for secure authentication and streamlined new user account creation at the hot-spot location.
The inventors recognized that 3GPP/Wi-Fi interworking mechanisms like ANDSF and Wi-Fi Alliance Hot-Spot 2.0 provide complementary mechanisms for integrated use of WLAN-based and cellular-based access networks. They also recognized that technology which leverages both types of mechanisms can provide increased integration, better performance, higher efficiency, better and more flexible services, etc.
A user equipment, UE, after establishing radio communications service with a first type of radio network, receives from the first type of radio network information including parameters for scanning for radio access points in a second type of radio network different from the first type of radio network. The UE scans access points in the second type of radio network based on the received information and detecting access point data and reports the detected access point data to the first type of radio network. In response to receiving a signal from the first type of radio network to switch radio communications service from the first type of radio network to one of the access points in the second type of radio network, the UE switches radio communications service from the first type of radio network to one of the access points in the second type of radio network.
Preferably, the switching of the radio communications service is a network-directed handover of the UE from the first type of radio network to one of the access points in the second type of radio network. For example, a situation may be detected indicating that the UE should begin the scanning step, and in response, the UE scans access points in the second type of radio network based on the received information and detecting access point data. The situation may include a weakening of signal strength or a lessening of signal quality from the first type of radio network.
The scanning parameters, for example, may include one or more rules indicating under what conditions the UE should scan access points and what specific information the UE should obtaining from the scanning and report to the first type of radio network. Example rules define one or more of the following: a frequency of scanning by the UE, a threshold defining a minimum signal parameter to initiate the scanning, a UE battery level to initiate the scanning, an application type on the UE to initiate the scanning, data processing unit utilization level, an UE accelerometer value to initiate the scanning, a UE position to initiate the scanning, or a mobility state of the UE to initiate the scanning Examples of the specific information include one or more of: a load of one or more access points in the second type of radio network, one or more supported roaming partners, a type of network security provided by the second type of radio network, a radio link performance associated with one or more access points in the second type of radio network, or a backhaul transport network performance of one or more access points in the second type of radio network.
In an example embodiment, the first type of radio network is a cellular radio network and the second type of radio network is a wireless local area network, WLAN. A non-limiting example is provided below where the cellular radio network is a 3GPP cellular radio network and the WLAN is a Wi-Fi network based on one or more IEEE 802.11 protocols. In a more detailed non-limiting example, the 3GPP cellular network includes an Access Network Discovery and Selection Function, ANDSF, which either pushes to the UE or has the UE pull a set of rules to be used by the UE to start scanning for Wi-Fi access, and wherein the specific information includes IEEE 802.11u PassPoint Access Network Query Protocol, ANQP, elements.
Another aspect includes a network node in the first type of radio network providing radio communications service to the UE. The network node sends to the UE information including parameters indicating how the UE is to scan for radio access points in a second different type of radio network separate from the first type of radio network. As a result, the network node receives from the UE access point data detected by the UE scanning access points in the second type of radio network in accordance with the sent information. The network node sends a signal to the UE instructing the UE to switch radio communications service from the first type of radio network to one of the access points in the second type of radio network based on the received access point data from the UE.
The following description sets forth specific details, such as particular embodiments for purposes of explanation and not limitation. But it will be appreciated by one skilled in the art that other embodiments may be employed apart from these specific details. In some instances, detailed descriptions of well known methods, nodes, interfaces, circuits, and devices are omitted so as not to obscure the description with unnecessary detail. Those skilled in the art will appreciate that the functions described may be implemented in one or more nodes using hardware circuitry (e.g., analog and/or discrete logic gates interconnected to perform a specialized function, ASICs, PLAs, etc.) and/or using software programs and data in conjunction with one or more digital microprocessors or general purpose computers. Nodes that communicate using the air interface also have suitable radio communications circuitry. Moreover, the technology can additionally be embodied within any form of non-transitory, computer-readable memory, such as solid-state memory, magnetic disk, or optical disk containing an appropriate set of computer instructions that would cause one or more processors to carry out the techniques described herein.
Thus, for example, it will be appreciated by those skilled in the art that block diagrams herein can represent conceptual views of illustrative circuitry or other functional units embodying the principles of the technology. Similarly, it will be appreciated that any flow charts, state transition diagrams, pseudocode, and the like represent various processes which may be implemented by computer program instructions that may be stored in a non-transitory, computer-readable storage medium and which when executed by one or more computers or processors cause the processes to be performed, whether or not such computer(s) or processor(s) is(are) explicitly shown.
Hardware implementation may include or encompass, without limitation, digital signal processor (DSP) hardware, a reduced instruction set processor, hardware (e.g., digital or analog) circuitry including but not limited to application specific integrated circuit(s) (ASIC) and/or field programmable gate array(s) (FPGA(s)), and (where appropriate) state machines capable of performing such functions.
In terms of computer implementation, a computer is generally understood to comprise one or more processors or one or more controllers, and the terms computer, processor, and controller may be employed interchangeably. When provided by a computer, processor, or controller, the functions may be provided by a single dedicated computer or processor or controller, by a single shared computer or processor or controller, or by a plurality of individual computers or processors or controllers, some of which may be shared or distributed. Moreover, the term “processor” or “controller” also refers to other hardware capable of performing such functions and/or executing software, such as the example hardware recited above.
The functions of the various elements including functional blocks, including but not limited to those labeled or described as a computer, processor, or controller, may be provided through the use of hardware such as circuit hardware and/or hardware capable of executing software in the form of coded instructions stored on non-transitory, computer-readable medium. Thus, such functions and illustrated functional blocks are to be understood as being either hardware-implemented and/or computer-implemented, and thus machine-implemented.
For the UE 16 and network node 18, scanning parameters may include one or more rules indicating under what condition(s) the UE should scan access points and what specific information the UE should obtain from the scanning and then report to the cellular radio network. For example, they may define one or more of the following: a frequency of scanning by the UE, a threshold defining a minimum signal parameter to initiate the scanning, a UE battery level to initiate the scanning, an application type on the UE to initiate the scanning, an UE accelerometer value to initiate the scanning, a UE position to initiate the scanning, or a mobility state of the UE to initiate the scanning Examples of information the UE may obtain during scanning and report to the network node may include one or more of: a load of one or more access points in the WLAN, one or more supported roaming partners, a type of network security provided by the WLAN, a radio link performance associated with one or more access points in the WLAN, or a backhaul transport network performance of one or more access points in the WLAN.
The following describes non-limiting example embodiments in a specific context where a first type of radio network is a 3GPP cellular radio network and a second type of radio network is a WLAN network corresponding to a Wi-Fi network based on one or more IEEE 802.11 protocols.
In this example context, the inventors determined that 3GPP's existing Access Network Discovery and Selection Function (ANDSF) is not sufficiently flexible or comprehensive because the existing ANDSF rules only allow UEs to associate with a Wi-Fi access point based on a list of service set identifiers (SSID), (each SSID is a MAC address for a corresponding Wi-Fi access point), available for the UE in a particular geographical location. For example, no selection rules are pushed to the UE to allow the UE to select a Wi-Fi Access Point network based on other criteria such as a load of the access point, supported roaming partners, the type of IP network security provided, radio link performance, and/or backhaul transport network performance of the access point. But the inventors recognized that Hot-Spot 2.0 certification provides access to these additional types data and that the discovery and selection mechanisms in Hot-Spot 2.0 are based on the collected data evaluation during a discovery phase prior to associating to any Access Point.
But there are also shortcomings in the HS2.0 selection mechanism. For example, it is based on a pre-provisioned set of rules stored in the UE that can be overridden by the user from a connection manager. Another shortcoming is the selection mechanism may only be enabled when the UE, or the user, activates a Wi-Fi interface to start scanning for a homogeneous extended SSID (HESSID). These shortcomings limit the effectiveness of HS2.0 selection results because the pre-provisioned rules are not network-managed or dynamic. The rules are network-managed so as to allow the network to steer the UE regarding radio access network to use. Accordingly, the network needs an overall view of different radio conditions across the multiple radio access technologies deployed. The network directing the steering allows optimization in directed the UE to an Access Point and transfers ome context data from the source access to the target access reducing the handover time. The rules are also dynamic to account for changing radio conditions and network conditions when steering the UE to the most optimal access when required. Therefore threshold for the different rules varies over time depending the variable radio and network conditions.
On the other hand, the ANDSF does support a network-controlled architecture to deliver network-managed policies, which can be refreshed and revised by the network as desired. Those policies may also be personalized based on the knowledge of the user if required. Accordingly, the technology in this example embodiment combines or integrates capabilities of HS2.0 and the ANDSF. For example, the ANDSF is augmented using HS2.0 functionality to include rules that provide a Wi-Fi network selection procedure based on data obtained from access points prior to UE authentication with a selected access point. The augmented rules may also be used as part of Wi-Fi's Inter-System Mobility Policies (ISMP) and Inter-System Routing Policies (ISRP). As a result, the 3GPP network can direct a UE switch, e.g., a handover, from 3GPP access to Wi-Fi access taking into account a variety of HS2.0 parameters, which is not possible with currently-defined mechanisms for network discovery and selection.
In this example context, the network node 18 is a 3GPP node or server includes a network-controlled Wi-Fi AP selection (NCWS) function corresponding to an augmented Access Network Discovery and Selection Function (ANDSF). The NCWS function may also reside in different parts of the 3GPP network such as part of the RAN, the core network (CN), or a service network. The NCWS either pushes to the UE or has the UE pull information (e.g., one or more sets of rules) to be used by the UE in scanning for Wi-Fi access UE to collect HS2.0 type information on different Wi-Fi APs. Based on this information from the network node, the UE may place its Wi-Fi radio interface circuitry into an HS2.0 scanning mode to allow the UE to perform a network discovery phase and probe APs in its vicinity using HS2.0 mechanisms. In this mode, the UE preferably does not associate to any Wi-Fi access point and hence stays connected to the 3GPP network. In this way, the 3GPP network controls handover to a particular Wi-Fi AP using a comprehensive platform of information to optimize the timing of the handover and the AP selected. As a result, this technology provides overall better end-user performance because the network type switch and AP selection take into consideration a variety of parameters like the load situation both in the source and target cells, radio conditions, ownership of the target Wi-Fi access point, and/or other factors.
As mentioned above, two types of rules may be pushed from the “network controlled Wi-Fi Access selection” function in the 3GPP network to the UE. One set of rules includes scanning conditions examples of which include one or more of the following:
1-a frequency of scanning operation. In between two scans the Wi-Fi radio can be turned off to save battery in the UE.
2-one or more thresholds defining the minimum signal strength of the 3GPP RAN to trigger a start of a Wi-Fi AP scan.
3-scanning based on battery level on the UE.
4-scanning based on the application type on the UE.
5-scanning based on data from the accelerometer in the UE if available.
6-scanning based on UE position
7-scanning based on the UE mobility (e.g. moving, stationary)
Other rules based on other parameters may also be used. Different rules may be used in different scenarios and implementations.
Another set of rules includes specific HS2.0 parameters that UEs should obtain from discovered access points referred to below as Wi-Fi scan data rules. The UE may use, in an example embodiment, 802.11u-based signaling to perform these queries on the different access points with SSIDs in one or more HESSIDs. These queried parameters may either all be reported back to the 3GPP network or a partial list may be reported back. Examples of HS2.0 parameters include Basic Service Set, BSS, Load of the Access Point, Received Signal Strength Indicator, RSSI, at the UE, Wide Area Network, WAN, Metrics, Operating Class, and Access Network Type.
The 3GPP RAN may send an access selection command or handover request to a UE ordering the UE to access a specific Wi-Fi access point selected by the 3GPP network node because, e.g., the AP fulfills certain criteria such as a load lower than a specified value, a signal strength stronger than a specific value, etc. The access point selection command to the UE may contain information outlining one or more conditions when the UE should connect to the selected Wi-Fi access point.
The associated signaling load on the UE and on the network may be controlled by limiting how often such rules, parameters, and/or conditions are updated. For example, only delta/difference information need be sent for updates. Similarly UE scan results may be reported to the network in terms of deltas from previous reports to reduce the signaling load. Triggering of reports may be periodic or event or condition-triggered or both. The scanning condition rules and reporting rules may be communicated to the UE either as broadcast information, as dedicated signaling, as pre-configured data, or some combination of these methods.
This reporting and the provisioning of the set of rules to the UE may take place on different levels. For example, it may be part of radio resource control (RRC) or non-access stratum (NAS) signaling or as part of an IP-level communication in the user plane of the 3GPP network.
At point 8), the 3GPP network node determines that a handover is desired or required and initiates at 9) the handover procedure by instructing the UE to associate to a neighboring access point, e.g., the MAC address of the AP is provided to the UE. The handover and selected AP information are based on the previously reported data by the UE. At 10), the UE controller places the Wi-Fi radio interface circuitry in “associate mode,” which is the regular mode for Wi-Fi radio communications. At 11), the UE selects the instructed Wi-Fi frequency and channel based on the received handover information. The UE starts the association and authentication procedure with the selected access point. At this point in time, there is no need to perform discovery as defined by HS2.0, as the network has already collected the discovery information at step 7. HS2.0 selection takes place where the UE associates with the network selected AP and starts an authentication procedure.
There are significant advantages to a network-controlled handover as compared for example to a UE-directed handover or a default Wi-Fi handover. For example, the 3GPP cellular network may be loaded, but still able to handle some type of traffic such as web traffic or chat applications. In that case, a video streaming application may be handled via the Wi-Fi access but the web and chat remain with the cellular network. Another advantage of network-controlled handover to Wi-Fi is the ability to trigger a handover to Wi-Fi when the load of the Wi-Fi network is warrant that handover. Absent this technology, the UE by default associates with Wi-Fi if it is available and provides a suitable signal strength. In this way, less desirable handovers from a cellular network to a Wi-Fi network may be reduced. Network-directed handovers lead to better utilization of radio resources (spectrum efficiency) and better end user performance because handover decisions are taken with knowledge of the full network load and radio conditions of all mobiles in the network rather than taken with the limited knowledge a UE has about its own radio situation and load situation of the target Wi-Fi access point. The technology also improves integration between cellular and other types of networks which is necessary for deploying other networks, like Wi-Fi networks, in a high-density manner. Another advantage is the technology saves battery in the UE by enabling the network to inform the UE when the Wi-Fi radio circuitry may be powered-off in between scanning periods.
Although the description above contains many specifics, these should not be construed as limiting the scope of the claims but as merely providing illustrations of example embodiments. It will be appreciated that the technology claimed fully encompasses other embodiments which may become apparent to those skilled in the art, and that the scope of the claims is accordingly not to be limited. Reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural and functional equivalents to the elements of the above-described embodiments that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed hereby. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved for it to be encompassed hereby. No element, block, or instruction used in the present application should be construed as critical or essential to the implementations described herein unless explicitly described as such. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Unclaimed subject matter is not dedicated to the public and Applicant reserves all rights in unclaimed subject matter including the right to claim such subject matter in this and other applications, e.g., continuations, continuations in part, divisions, etc.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/SE2012/050834 | 7/13/2012 | WO | 00 | 1/12/2015 |